A personal flotation device (abbreviated as PFD; also referred to as a life jacket, life preserver, Mae West, life vest, life saver, cork jacket, buoyancy aid or flotation suit) is piece of equipment designed to assist a wearer, who may be either conscious or unconscious, to keep afloat. PFDs are available in different sizes to accommodate variances in body weight. Designs differ depending on wearing convenience and level of protection.